The present invention relates to a developing apparatus which comprises a developing agent carrier facing an image bearing member such as a drum-shaped photosensitive member, a rotatable stirring member extending parallel to the developing agent carrier, and a frame containing the developing agent carrier and the stirring member.
The stirring member of the developing apparatus of this type includes a shaft and a plurality of diskshaped or elliptic stirring blades arranged at regular intervals along the axial direction of the shaft and inclined at an angle to the axis of the shaft. As the shaft rotates, the stirring blades stir the developing agent (hereinafter referred to simply as toner), and convey the toner in an oscillatory manner along the axial direction of the shaft.
The upper halves of the stirring blades (upper portion of the stirring member), which face a toner hopper located above, mainly stir the toner, while the lower halves of the blades (lower portion of the stirring member) surrounded by the frame or casing mainly serve, in cooperation with the casing, to positively convey the toner along the axial direction.
According to such a conventional arrangement, however, trouble will be caused if a copying machine incorporating the developing apparatus is set on a slanting surface. If the toner is stirred with the shaft inclined, it will be collected by degrees at one side of the region corresponding to the lower end of the inclined stirring member, so that the toner at the upper end portion will gradually be reduced. Thus, the supply of the developing agent to the developing agent carrier varies along the axial direction of the stirring member, exerting a bad influence on an image density.